Changes in blood proteins during menopause indicate the possible origins of brain fog, and how to prevent future risk of dementia.
Some proteins linked to inflammation and with a negative impact on brain function are present in higher levels in the blood of menopausal women: the results of a study published in Nature Medicine They offer a further clue as to why menopause is a stressful transition phase for the brain, and pave the way for possible new treatments to protect female brain health.
Menopause and the brain: more connected than you think
Women are more likely than men to develop dementia in later life, and not just because they live longer: menopause could play a role. An early onset of menopause is associated with a higher risk of Alzheimer’s, and some of the classic symptoms that emerge at this stage of life – such as brain fog, mood and sleep disorders, or memory problems – are linked to the fact that the brain plays an important role in menopause, and is also vulnerable to its effects.
As explained above Sciencethe brain is in fact lined with hormone receptors and produces hormones in turn: the pituitary gland or pituitary gland, a small gland located at the base of the skull, produces follicle-stimulating hormone, the levels of which rise when the ovaries in menopause drastically decrease the production of estrogen and progesterone.
Without estrogen, specialized neurons in the hypothalamus cause the dilation of blood vessels that cause night sweats and hot flashes during menopause. Frequent vasomotor symptoms such as those described are associated with suffering of the white matter (the set of nerve fibers in the brain and spinal cord) and with higher markers of Alzheimer’s disease. However, distinguishing which processes depend on menopause itself and which are generally typical of aging is very complex.
Harmful proteins
Menopause is a biological event that marks the definitive cessation of menstruation and female fertility: by definition, it occurs after 12 consecutive months without cycles. A group of neuropsychologists from the University of California in San Francisco followed 80 women in premenopause, perimenopause (i.e. the transition period between the fertile phase and actual menopause) and postmenopause. Blood tests of the women identified a molecular signature of menopause, made up of 16 proteins linked to brain health that were higher in women who had officially passed this threshold.
Two of these proteins are linked to Alzheimer’s, others are linked to the health of neurons and synapses, the connections between neurons.
Still others are cytokines, inflammatory signaling proteins, and were higher in women who had episodes of night sweats. Madeline Wood Alexander, first author of the study, defines the detected protein signature as a “persistent inflammatory response, which could be activated during the menopause transition.”
A new trail to follow
According to the researchers, the problem could depend on the pituitary gland and the high production of FSH rather than on the reduction of female reproductive hormones. Studies in mice suggest that this hormone impacts neurons in a way that can accelerate the path to Alzheimer’s disease, and that blocking its action can hinder this degeneration. Many of the proteins found are also, the authors found, elevated in women in their 60s and 70s who end up developing dementia.
Overall, the study seems to highlight which, among the countless protein changes linked to menopause, are the ones to pay attention to most, to protect brain health. To confirm these results, however, studies will be needed on larger samples and which follow the patients for a few years, monitoring the fluctuations of proteins in the blood.
“All women with intact ovaries will go through spontaneous menopause during adulthood, but most of them will not develop Alzheimer’s disease,” Wood Alexander reminds us to reassure. Scientists “can exploit this phase to understand who is following a trajectory of vulnerability and who, instead, is following a trajectory of greater resilience.”
